The subject matter of the present invention relates to a shaped charge for use in a perforating gun, the shaped charge including a main body of explosive which further includes sym-triaminotrinitrobenzene (TATB) and a primer, more sensitive than TATB, adapted to initiate the detonation of the main body of explosive. The subject matter also relates to other downhole explosive devices, such as casing and tubing cutters, boosters, detonating cord and detonators.
Shaped charges include a main body of explosive, known as a secondary explosive, which detonates when a primary explosive pellet detonates in response to a detonation wave propagating in a detonating cord. When the main body of explosive detonates, a jet is formed which propagates outwardly from the shaped charge. Shaped charges have been used in perforating guns, and perforating guns are used to perforate a formation penetrated by a wellbore. When the jet is formed from the shaped charge in the perforating gun, the jet perforates the formation and, in response, a wellbore fluid is produced from the perforated formation. The length of the jet produced from the shaped charge will determine the length of the perforation in the formation and potentially the amount of wellbore fluid produced form the perforated formation. However, the length of the jet propagating from the shaped charge in the perforating gun is determined, among other parameters, by the type of explosive which is used to constitute the main body of explosive in the shaped charge. For high temperatures, above HMX temperature limits, an explosive known as I-INS has been used as the main body of explosive in the shaped charges in the perforating gun. In addition, shaped charges which utilize HNS as the main body of explosive have performed satisfactorily in the past. However, development efforts continue to focus on better apparatus, compositions, and methods to produce a longer jet propagating from the shaped charge. If a longer jet is produced from a detonated shaped charge, the longer jet would produce a longer perforation in the formation, and a longer perforation in the formation penetrated by the wellbore could potentially increase the production of wellbore fluid from the perforated formation. Therefore, a primary object of this invention relates to providing an improved explosive composition adapted for use in a shaped charge for producing a longer jet from the shaped charge when the charge is detonated. Since the shaped charge is adapted for use in a perforating gun for perforating a formation penetrated by a wellbore, when the perforating gun is detonated, the longer jet will produce a longer perforation in the formation, and the longer perforation will cause increased quantities of wellbore fluid to be produced from the perforated formation.